Oscillators: raw waveforms, phase, sync, and unison

Everything downstream in subtractive synthesis — filters, envelopes, effects — can only sculpt what the oscillators supply. This module builds the whole task of choosing and animating raw sources on purpose: in a live-coding or soft-synth rig (Surge XT, Serum, Vital), you rarely have time to fix a thin source later, so a trance supersaw, a warm PWM pad, or an aggressive synced lead must be right at the oscillator stage. The capstone asks for exactly that: four contrasting sources — a chord-stacked unison saw, a PWM pulse, a synced lead, and a tuned noise layer — each verified on a spectrum analyzer before any filter touches them.

The arc starts supported. First exercises revisit a single pulse wave, hearing how duty cycle sets harmonic content, then adding an LFO — the “sweeping pulse width with an LFO” move — to turn one static oscillator into a chorused, living pad. From there the learner stacks: detuned unison copies for width, a sub oscillator an octave down for weight (guided by the “sub oscillator adds low-end weight” procedure), and stack mode or semitone transposition to fold a fifth or a full chord into one patch — the chord requirement of the saw leg. The “supersaw lead” recipe serves as a JIT how-to for the fat-saw leg of the capstone, while hard sync’s phase-reset behavior explains the screaming lead leg. The noise leg draws on the noise-color cluster — white’s flat spectrum versus pink and brown rolloffs, and looped noise as the trick that makes a noise layer tunable. Phase atoms — start phase, retrig vs. random, and cancellation when layering — are the debugging lens when a bass mysteriously thins out or attacks click.

Required atoms gate the capstone directly: without pulse-width harmonics, sync, unison, stack/interval stacking, phase, and noise-color knowledge, the four sources cannot be designed or verified. Supporting atoms enrich rather than gate — VCO voltage control and 1V/octave connect the ideas to analog and modular hardware, band-limited oscillators explain why digital saws stay clean, and the Surge XT oscillator atoms map the concepts onto one concrete free instrument. Drill unison detune, PWM setup, and sub layering until they are reflexive; they recur in nearly every patch you will build after this.

Runnable examples

Generated from the context/ instrument corpus by concept (redistributable idioms only). Do not edit — regenerate with gen-module-examples.mjs.

detune-thickening

saw [110, 110.2] >> audio

_{punctual-0009 · CC0-1.0}

d1 $ note "c2" # sound "supersaw" # detune 0.3

_{tidal-0039 · CC0}

bitcrush

s("bd*4").crush(4)

_{strudel-0022 · CC0}

d1 $ sound "bd*4" # crush 4

_{tidal-0021 · CC0}

chord-extension

[60,63,67,70] @=> int ch[]; SawOsc s => ADSR e => dac; e.set(2::ms,120::ms,0,2::ms);
for(0=>int i;i<ch.size();i++){ Std.mtof(ch[i]) => s.freq; e.keyOn(); 150::ms => now; }

_{chuck-0035 · MIT}

mono-bass

mono (saw [110,220,330]) >> audio

_{punctual-0013 · CC0-1.0}

reese-bass

use_synth :dsaw; play :e1, detune: 0.3, cutoff: 70, release: 0.4

_{sonicpi-0039 · CC0}